The present invention is directed to a material handling system and, in particular, to a label application and method for use with such material handing system. The invention is particularly adaptable for use in the application of a particular label selected from a plurality of different labels to articles being conveyed by a conveying surface of the material handling system. The invention is particularly adapted for use in the application of different labels, wherein at least one of the labels is a radio frequency identification (RFID) tag.
RFID tags provide unique identification codes for articles or a group of articles, such as carried by a pallet, carton, or the like. The advantage of an RFID tag is that it may be read remotely using radio frequency signals emitted by an RF reader which then, in turn, receives RF signals sent by the RFID tag. One difficulty with RFID tags is that the product or article upon which the tag is placed, or the packaging material for the product, can affect the performance of the tag. For example, if the article is made up of a large quantity of a liquid, such as water, bleach, or the like, the article tends to absorb signals emitted by the RFID tag, thereby distorting the signals. In a similar fashion, if the article contains an appreciable amount of metal, such as pop cans, or the like, the metal may distort the RFID signals emitted by the RFID tag. In contrast, if the article is made from a material that does not significantly absorb or reflect RFID tags, such as paper, then the article does not affect the signals emitted by the RFID tag appreciably.
RFID tags are provided by various suppliers. Some RFID tags are high performance tags that are capable of emitting relatively clear RFID signals even in the presence of distorting articles, such as articles containing a significant amount of liquid or metal. Such high quality RFID tags typically come at a premium price. Other RFID tags come at a low cost, but may be low performance tags that are not as capable of emitting clear radio frequency signals in the presence of liquids, metals, or the like. Therefore, if a supplier supplies articles having various characteristics, which differently affect the radio frequency signal generating capabilities of an RFID tag, the supplier will use the more expensive RFID tags in order to ensure that the tags will emit radio frequency signals when probed.